chinery for rapid seedbed preparation, which will facilitate growing an extra crop during the year). Rapid population growth in rural areas in which the supply of arable land is limited results either in a fragmentation of farms from one generation to the next, or in an enforced migration of younger sons and their families to towns and cities. The average size of farms in the Punjab of West Pakistan has decreased by about 50 percent in one generation. The effects of farm fragmentation can be overcome by the formation of agricultural cooperatives among the small farmers, but experience in less developed countries shows that this usually occurs only under the impetus of strong government or outside encouragement. Urbanization In most less developed countries, cities are growing more rapidly than total populations, at least partly because stagnant rural economies have not been able to absorb rural population growth. In one carefully studied region of the Punjab in northwestern India, the rate of emigration during the 1950's equaled half the rate of natural increase of population. The situation has been considerably improved during the last few years by the rural prosperity resulting from the agricultural revolution described earlier. But in other regions, such as East Pakistan, where rural population densities average more than 1,200 people per square rnile, the labor/land ratio cannot be much increased even with the multiple-cropping and increased crop yields brought about by the new technology. With present rates of population growth in the Province, room must be found in cities and towns during the next 20 years for some 15 million people. It may be impossible to accommodate these numbers in existing cities, and if so, new cities and towns and new industries must be created on a very large scale. Planners and policymakers will have hard choices to make in dividing scarce resources between investments to provide industrial and service jobs, and construction of housing, roads, water supply and sewage disposal systems, and other elements of urban infrastructure. Much experimental research needs to be done on lowering these costs of urban development. Other choices must be made between developing many small cities and towns of ten to fifty thousand inhabitants or large cities with millions of people. These choices should be based on a careful analysis of the full range of social and economic costs and benefits of each kind of urban place, the functions that can be filled by towns and those that must be reserved for cities, and the possibilities of influencing migrant behavior. One advantage of having many urban centers is that people may continue to live in the country and commute to a nearby city or town for employment. Thus, the small cities of Comilla in East Pakistan and Ludhiana in the Indian Punjab draw many villagers for daytime employment who return on bicycles and buses to their rural homes at night.